1. Field of the Invention
The subject invention pertains to the field of wire winding apparatus and more particularly to an apparatus for traversing wire or the like back and forth across the width of a reel during the winding process so as to lay down even, uniform layers of wire.
3. Prior Art
In the winding of wire or the like onto reels, it is generally necessary that the wire be advanced back and forth along the width of the reel during the winding process so as to form, as nearly as possible, uniform layers of wire, each such layer comprising individual coils of wire having a desired pitch.
In the prior art, translation winders are known. Such winders reciprocate the reel laterally with respect to the incoming wire so that the wire is wound onto the reel at right angles to the reel axis of rotation. Translation winders have serious shortcomings, however, since such winders require a mechanism which must simultaneously rotate the reel about a given axis and reciprocate the reel along such axis of rotation. Such a mechanism must be capable of handling fully loaded reels, which weigh up to a few thousand pounds, and are, therefore, mechanically complex and expensive.
Other wire winders known in the prior art operate with the take-up reel fixed in place. In these winders, some form of reciprocating wire guiding mechanism is disposed between the reel and the wire source. The mechanism is typically a pulley or sheave, having an axis of rotation parallel to the reel's axis of rotation, which traverses the width of the reel between the reel flanges. The traversing pulley, which is normally V-grooved to contain the wire, reciprocates at a rate such that coils of wire are wound onto the reel in uniform layers. However, when the traversing pulley approaches an extreme position, the angle between the wire entering the pulley and the plane formed by the pulley groove often becomes large enough to cause the wire to have a tendency to climb the walls of the pulley groove and, perhaps, to be thrown from the pulley. One such apparatus is disclosed in U.S. Pat. No. 3,677,483 issued to Werner Henrich.
In addition to the disadvantageous tendency of the above-described prior art winders to throw the incoming wire from the traverse pulley when the latter approaches its extreme position, such winders also tend to rub, scuff and mark the wire. When wire enters or leaves a pulley at other than in the central plane of the groove of the pulley, the non-coincidence of the direction of wire travel and the direction of motion of the pulley groove wall causes the wire to be rubbed, scuffed and marked by the groove wall. Moreover, such non-coincidence of the directions of motion of the wire and groove wall increases the friction between them, thereby requiring an increase in the pulling force applied to the wire, i.e., the wire tension, by the take-up reel drive. Such increases in wire tension are non-uniform and tend to damage the wire.
One prior art solution for reducing the tendency of the wire to climb the walls of the pulley groove is to use a traverse pulley having a very wide angle V-groove. The wire can enter such a pulley at an angle substantially offset from the groove plane without having a tendency to climb the groove walls. Such pulleys, however, are not capable of accurately guiding the wire onto the reel; therefore, the layers formed on the reel are uneven. Thus, the primary purpose of the traversing pulley is defeated.
The angle between the wire, as it approaches the traversing pulley and the pulley groove plane, can also be reduced by placing the wire source a substantial distance from the traversing pulley. Although this solution reduces the tendency of the wire to be thrown from the pulley, the increased length of suspended wire between the wire source and the traversing pulley causes the suspended length of wire to vibrate and possibly stretch, thereby permanently damaging the wire. Furthermore, the amount of costly floor space needed for such a machine is increased substantially, and protective guards must be utilized in order to protect personnel from being injured by the suspended wire.
Another attempt to reduce the angle at which the incoming wire approaches the traversing pulley is the use of a pair of rollers, disposed between the wire source and the pulley. The closely spaced rollers are free to rotate about axes which are normal to the wire passing therebetween. The rollers move along with the traversing pulley so that the wire is guided to the traversing pulley at a constant angle. U.S. Pat. No. 3,080,128 issued to C. E. Hauer discloses the use of rollers in this manner. Although the rollers guide the wire to the traversing pulley so that the wire approaches the pulley at substantially right angles to the pulley axis of rotation, the rollers tend to damage the wire, expecially if wire of a small guage is being wound. This is because space limitations usually require the use of small diameter rollers so that the additional sharp bending produced by the rollers causes the wire to become abraded and scuffed. Furthermore, such bending causes cold work hardening of the wire, resulting in a loss of anneal.
Still another prior art configuration involves the use of a traversing pulley which is pivotally mounted so that the pulley is free to pivot about an axis which is at right angles to the pulley axis of rotation. In these configurations, a fixed input pulley, disposed between the wire source and the traversing pulley, is typically used. Since the traverse pulley is free to pivot and thereby accommodate, to a large extent, the wire approaching and exiting the pulley, the angle of the wire with respect to the pulley groove plane is reduced; therefore, the disadvantages discussed above; e.g., the tendency of the wire to climb the walls of the traverse pulley, among others, is somewhat reduced. Although this scheme is an improvement over the other prior art traversing apparatus discussed earlier, the wire angle approaching and exiting the traverse pulley is not completely eliminated. Furthermore, the fixed input pulley must accommodate the wire leaving it over a full range of angles, and, therefore, the input pulley tends to throw the wire, or abrade the wire surface or otherwise damage the wire.
Other prior art traversing apparatus, having all or some of the above shortcomings, are set forth in U.S. Pat. No. 1,657,308 issued to Jespersen; U.S. Pat. No. 3,289,956 issued to Sjogren and U.S. Pat. No. 2,254,220 issued to Hubbard.
Disclosed herein is a traverse apparatus which overcomes the above-described limitations of the prior art. This apparatus is capable of winding wire onto a reel so as to form even, uniform layers of coiled wire. Small guage wire can be wound without tension variations, cold work hardening, scuffing, rubbing or marking the wire, and without throwing the same. Furthermore, the novel apparatus disclosed herein is simple, low in cost, utilizes a minimum amount of floor space and presents little hazard to personnel working in the area.